This invention relates to a temperature sensor having an expansion diaphragm assembly for operating a snap action switch and further including a liquid-filled sensor tube and a capillary tube which serves for maintaining communication between the sensor tube and the expansion diaphragm assembly.
Sensor devices of the above-outlined type are known wherein the expansion diaphragm assembly is formed of two resilient box halves which are joined to one another along their edge zone by means of welding or soldering. One box half is, through an opening, coupled with a capillary tube through which passes, subsequent to heating, the heat-expandable liquid contained in the sensor tube. The increase of the volume within the expansion diaphragm obtained in this manner causes the other closed box half to be displaced through a path which is utilized to actuate a snap action switch.
In the known structures the box half provided with the opening is attached to a carrier plate either directly or by means of a usually cylindrical intermediate component. The intermediate component may, in a conventional manner, be held in a desired value setting device.
The above-outlined known structures all have the disadvantage that for the manufacture of the expansion diaphragm assembly two box halves are necessary which have to be welded or otherwise joined to one another and to a carrier plate or, as the case may be, to a usually expensive intermediate component.
It is a further disadvantage of the known arrangements that in most cases a large structural height is required so that the total structural height of the temperature sensor (thermostat) renders it inconvenient or unadapted for use in certain environments, for example, in household appliances.